Decorative film

ABSTRACT

A decorative film prepared by a transcription printing of the present invention is capable of providing a decorative film with excellent durability. A decorative film of the present invention comprises a primer layer formed on the adhesive layer, in which is composed of a resin having a releasing property to a releasing sheet for transfer and a functional group in a molecular chain to which the cross-linking agent reacts, a decorative layer including an ink, in which is formed on the primer layer, and a curable resin layer cured by radiation, in which is formed on the primer layer, and contains a cross-linked resin material between the adhesive layer and the primer layer.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation-In Part application of, and claimspriority from, U.S. patent application Ser. No. 10/377082 entitled“Decorative Film-like Material and Decorative Sheet” filed on Feb. 27,2003.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a decorative film and automobile partsdecorated thereby which can be used for construction componentsincluding exterior walls, street doors and exteriors and interiors ofvehicles and vessels, billboards and signs.

2. Description of Related Art

For example, in order to improve design for construction componentsincluding exterior walls, street doors and exteriors and interiors ofvehicles and vessels, billboards and signs, sometimes decorative filmswith some dressing like coloring are applied or dressed decorative filmsare bonded to a substrate.

Heretofore, as decorative films excellent in design with goodoperational efficiency, decorative coating films with a film bodyprovided which is composed of a printing layer printed on a releasingsurface of a releasing sheet and having a releasing property to areleasing surface and a coated layer formed by a kind of curable resincoatings selected from the group consisting of a resin coating cured byheat, a resin coating cured by electron rays, a resin coating cured byradiation, and a resin coating cured by ultra violet rays cured aftercoating in such a way as to cover a surface of the printing layer havebeen suggested (Japanese Unexamined Laid-open Patent Publication2001-1483).

In using this decorative film, a bond is applied to a printing surfaceat an operational site and bonded to a substrate to which a dressing isapplied or an adhesive layer is provided on a printing layer and makesit adhere to a substrate.

When a bond is applied on a printing layer or an adhesive layer isformed on a printing layer and is adhered to a substrate to which adressing is applied by forming an adhesive layer, since a bond or adecorative layer or an adhesive layer are attached only by theiraffinity, in order to continuously use under harsh condition over longperiod of time including the use outdoors and the like, the performancehad to be improved so that both layers are hard to peal off.

Therefore, further improved durability has been desired for the purposeof modifying exterior and interior of automobiles. The reason is thatwhen these decorative films are used as a dressing for exterior parts orautomobile bodies bonding or applying the decorative film to automobileparts, these films are used in outdoors under harsh condition. On theother hand, when decorative films are used as interior parts, inside ofan automobile is in a harsh condition in summer.

SUMMARY OF THE INVENTION

According to the first aspect of the present invention, a decorativefilm comprises:

-   -   an adhesive layer including a cross-linking agent;    -   a primer layer formed on the adhesive layer;    -   a decorative layer including an ink and formed on the a primer        layer; and    -   a curable resin layer cured by radiation, formed on the        decorative layer,    -   wherein the primer layer contains a resin having a functional        group in a molecular chain to which the cross-linking agent        reacts and a releasing property to a releasing sheet for        transfer, and a cross-linked resin material is included between        the adhesive layer and the primer layer.

For information, a colorless decorative film can be obtained byproviding a decorative film without the decorative layer in thecomposition of the decorative film.

Further preferably, the decorative film comprises the cross-linkingagent included in the adhesive layer which is an isocyanatecross-linking agent and a functional group of a molecular chain of theresin used in the primer layer which is at least either carboxyl groupor hydroxyl group. 10011] Further preferably, the decorative film iscomposed of which the cross-linking agent included in the adhesive layeris an isocyanate cross-linking agent and the primer layer contains vinylchloride vinyl acetate copolymer resin or acrylic resin in a total ofnot less than 25% by weight.

In addition, the decorative film may have a releasing sheet to protectthe adhesive layer applied on the adhesive layer.

A production method of a decorative film comprises:

-   -   the first step in which a primer layer is formed by applying a        resin having a functional group in a molecular chain to which a        cross-linking agent reacts and a releasing property to a        releasing sheet for transfer on a surface of the releasing        sheet,    -   the second step in which a decorative layer including an ink is        printed on the primer layer;    -   the third step in which a curable resin layer cured by radiation        is applied on the decorative layer:    -   the forth step in which the primer layer and the decorative        layer are transferred from the releasing sheet for transfer to        the curable resin layer when the curable resin layer is cured by        radiation;    -   the fifth step in which an adhesive including the cross-linking        agent is applied on a releasing sheet to form an adhesive layer,        and then, the adhesive layer is adhered to the exposed primer        layer by peeling off the releasing sheet for transfer; and,    -   the sixth step in which a cross-linked resin material is        provided between the primer layer and the adhesive layer as well        as heat curing of the film obtained in the fifth step brings the        adhesive layer to transfer from the adhesive layer to the        releasing sheet.

For information, a colorless decorative film can be obtained byproviding a decorative film without the decorative layer in thecomposition of the decorative film.

And in particular, the present invention relates to an automobile onwhose surface a cosmetic coating is bonded via a bond; the cosmeticcoating is composed of a decorative film having at least a primer layerand a resin layer cured by radiation formed by curing after coating insuch a way as to cover a surface of the primer layer; and a primer layerof the cosmetic coating and the bond are united and integrated with anisocyanate cross-linking agent contained in the bond reacted with afunctional group of a molecular chain of a resin contained in the primerlayer.

Since a decorative film in the present invention is as above mentioned,the present invention is capable of providing a decorative film in whicha release from a substrate is hard to occur even when used for a longperiod of time since a primer layer and a bond or a primer layer and anadhesive layer are firmly bonded.

Further, automobile parts and an automobile excellent in design and indurability modified by this decorative film can be provided.

Other objects and the features will be apparent from the followingdetailed description of the present invention with reference to theattached drawings.

The above and/or other aspects, features and/or advantages of variousembodiments will be further appreciated in view of the followingdescription in conjunction with the accompanying figures. Variousembodiments can include and/or exclude different aspects, featuresand/or advantages where applicable. In addition, various embodiments cancombine one or more aspect or feature of other embodiments whereapplicable. The descriptions of aspects, features and/or advantages ofparticular embodiments should not be construed as limiting otherembodiments or the claims.

BRIEF DESCRIPTION OF DRAWING

The accompanying figures are provided by way of example, withoutlimiting the broad scope of the invention or various other embodiments,wherein:

FIG. 1 is a sectional view showing a decorative film in the colorlessembodiment of the present invention.

FIG. 2 is a sectional view showing a decorative film in the colorlessembodiment of the present invention.

FIG. 3 is a sectional view showing a decorative film in the secondembodiment of the present invention when a decorative layer is provided.

FIG. 4 is a sectional view showing a decorative film in the secondembodiment of the present invention when a decorative layer is provided.

FIGS. 5(a) and (b) are sectional views showing a step flow of aproduction method of a decorative film in the colorless embodiment ofthe present invention.

FIGS. 5(c) and (d) are sectional views showing a step flow of aproduction method of a decorative film in the second embodiment of thepresent invention.

FIGS. 5(e) and (f) are sectional views showing a production step of adecorative film in the colorless and second embodiment of the presentinvention into a decorative film respectively.

DETAIL DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, a decorative film in the embodiment of the presentinvention is explained referring to FIGS. 1 to 5.

In the first embodiment of the present invention, as shown in FIG. 1, adecorative film 10 has at least a primer layer 11 and a resin layer 12cured by radiation formed by curing after coating in such a way as tocover a surface of the decorative layer 12. On the other hand, as shownin FIG. 2, a decorative film 20 of the present invention has at least aprimer layer 21 and a resin layer 22 cured by radiation formed by curingafter coating in such a way as to cover a surface of the primer layer,an adhesive layer 23 formed on a surface of a primer layer side, and areleasing sheet 24 which protects an adhesive layer.

In addition, in the second embodiment of the present invention, as shownin FIGS. 3 and 4, a decorative film is added to the first embodiment anddecorative layers 35 and 45 are provided between resin layers 12 and 22cured by radiation.

Since a resin used in primer layers 11 and 21 achieves the property thata release between layers is hard to occur even when used for a longperiod of time, it is necessary to have a functional group in amolecular chain of a resin molecule which reacts to a cross-linkingagent. In the meantime, it is preferable that a functional group has atleast either carboxyl group or hydroxyl group in view of easy reactionto a cross-linking agent.

Further, chemical modification can be applied to a molecular chain of apolymer resin and such a functional group with carboxyl group orhydroxyl group introduced can be used.

As such resins, resins which are selected at least from one componentcontaining polyester resin, alkyd resin, amino resin, acrylic resin,epoxy resin, vinyl chloride resin can be used. Further, when resins havecompatibility, these resins can be mixed or can be used in a state ofmulti layers.

Further preferably, primer layers 11 and 21 contain a thermoplasticresin in not less than 25% by weight, and even more preferably 50% byweight which contains at least either of vinyl chloride vinyl acetatecopolymer resin and acrylic resin. Vinyl chloride vinyl acetatecopolymer resin to be used is not specifically limited, but it ispreferable that the weight ratio of vinyl chloride/vinyl acetate is 92/8to 75/25, and the average molecular weight is within the range of 25000to 40000. Acrylic resin preferably includes acrylic polyol.

For information, either of vinyl chloride vinyl acetate copolymer resinmay be contained in total of 100% by weight.

Although a thickness of primer layers 11 and 21 is not specificallylimited, a thickness is preferably about 0.3 μm to 50 μm, and morepreferably, 1 μm to 10 μm. That is, when primer layers are too thick,flexibility of a decorative film is deteriorated and in the case of asubstrate having uneven surface, a decorative film may not be wellfitted to a substrate. On the other hand, when primer layers are toothin, a bonding property to a bond or an adhesive is not satisfactoryenough to achieve the object of the present invention.

In order to produce such primer layers 11 and 21 preferably, it ispreferable that a resin which composes primer layers is formed bycoating on a releasing sheet for transfer 35, followed by transferring.In this case, it is preferable that a resin which composes primer layershas releasing property to a releasing surface. The above exemplifiedresin also has such a property as well.

It is preferable that a cross-linking agent is contained in a primerlayer 11 of a decorative film 10 in order to strengthen a bondingbetween layers. Unless a cross-linking agent is contained in primerlayers, it is necessary that a cross-linking agent is contained in abond. By adopting such a composition, chemical bonding can be generatedbetween a primer layer and a bond after bonding a decorative film to asubstrate.

Further, since a cross-linked resin is contained by a cross-linkingagent between layers of a primer layer 21 and an adhesive layer 23, abonding between layers gets strong in the case of a decorative film 20.

Examples of such cross-linking agents capable of obtaining such aproperty include isocyanate cross-linking agents, epoxy cross-linkingagents, and aluminum chelate cross-linking agents. These cross-linkingagents play a role in strengthening a bonding between layers since thesecross-linking agents chemically react with a functional group of resinmolecules of primer layers 11 and 21 in particular, with carboxyl groupor a hydroxyl group thereby contributing to having a three dimensionalchemical structure over a surface of primer layers and a bond oradhesive layers. In particular, when vinyl chloride vinyl acetatecopolymer resin are used for primer layers 11 and 21, using isocyanatecross-linking agents which is likely to react with hydroxyl group of aresin as a cross-linking agent is further preferable since chemicalreaction between layers is strengthened.

In order to draw such a property, it is preferable to mix across-linking agent in primer layers 11 and 21 or an adhesive layer 23.Conventional mixing method can be adopted. As for mixing ratio, thesubstantial ratio of a cross-linking agent to a resin composing a primerlayer or an adhesive composing an adhesive layer is preferably about0.02% to 6%. When a ratio of a cross-linking agent is too low, a bondingeffect between layers is not satisfactory. On the other hand, when aratio of a cross-linking agent is too high, a bonding effect isunchanged from a certain level and therefore useless.

As for resins used for resin layers 12 and 22 cured by radiation, knownresins can be used as long as they are non-solvent type resins cured byradiation, but light-cured olygomers having double bond includingacrylic group, methacrylic group, allyl group, and vinyl group (forexample, urethane acrylate resin) and monomers (for example,tripropylene glycol diacrylate) or compounds thereof are preferably usedas main components.

Coloring components can be contained in resin layers 12 and 22 cured byradiation. As coloring components to be used, known coloring componentscan be used as exemplified in an explanation of a decorative layermentioned hereinafter.

Further, as required, ultra violet ray absorbent, other lightstabilizer, anti-oxidant, anti-aging agent, leveling agent, anti-staticagent, fixing agent, plasticizer, lubricant, organic filler, inorganicfiller, such metal (compound) oxide fine particles as titanium oxide,zinc oxide, ITO and the like having ultra violet ray absorption power ornear-infrared ray absorption power can be added as additives in a resinlayer cured by radiation.

In addition, resin layers 12 and 22 cured by radiation can be composedof multiple layers. In this case, different coloring components can becontained respectively. When a resin layer cured by radiation iscomposed of multiple layers and different coloring components arecontained respectively, design can further be improved.

A thickness of resin layers 12 and 22 cured by radiation is 10 μm to 500μm, and preferably, 20 μm to 300 μm. When a thickness of resin layers 12and 22 cured by radiation is less than 10 μm, a design is notsatisfactorily shown, a decorative layer protecting effect is low when adecorative film is provided which is mentioned later, and therefore, itbecomes difficult to take a role as a decorative film. On the otherhand, when a thickness of resin layers 12 and 22 cured by radiationexceeds 500 μm, flexibility of a decorative film decreases and handlingbecomes difficult.

Although forming methods of resin layers 12 and 22 cured by radiation isnot specifically limited, such methods can be exemplified that after acoating step in which a resin composition cured by radiation is coatedon a decorative layer surface with a specific thickness including barcoat method, roll coat method, air doctor coat method, blade coatmethod, squeeze coat method, air knife coat method, reverse roll coatmethod, gravure coat method, transfer coat method, fountain coat method,slit die coat method, or lip die coat method, and the like, followed byheating a resin composition or irradiating ultra violet rays, electronrays, radioactive rays, and the like. When a resin cured by electron rayis used as a resin, electron ray irradiation devices are notspecifically limited, and for example, such electron ray irradiationdevices with Van der Graaf scanning method, double scanning method, andcurtain beam method can be used and among them, an electron rayirradiation device is preferable since it is relatively low in cost andradiation output of electron ray is large. Necessary accelerationvoltage is selected depending on a thickness of a coated film.Atmosphere of electron ray irradiation is in inert gases containing nonitrogen burning gas, oxygen, or ozone.

81 In addition, acceleration voltage in electron ray irradiation ispreferably 100 kV to 500 kV. In order to improve transmission rate ofelectron ray, acceleration voltage is preferably not less than 250 kVAlthough absorption dose of electron ray is not specifically limited aslong as desired cure is provided, generally, the absorption dose is 0.1Mrad to 7 Mrad and preferably 0.2 Mrad to 5 Mrad. When absorption doseof electron ray is less than 0.1 Mrad, cure of resin composition curedby electron ray by electron ray irradiation is not satisfactory. On theother hand, when absorption dose of electron ray exceeds 7 Mrad,sometimes a seat type substrate is deteriorated or tarnished. Further,it is not preferable from a view point of energy saving.

A surface of resin layers 12 and 22 cured by radiation can be covered bya metal layer and by a protection film.

In order to improve designs, such a decorative film that is providedwith decorative layers 35 and 45 between primer layers 11 and 21 andresin layers 12 and 22 cured by radiation can be prepared. As for thespecific embodiment of decorative layers 35 and 45, when a decorativelayer is formed by printing, although an ink to be used is notspecifically limited, acrylic resin, fluoride resin, inorganic resin,and the like are exemplified. Among them, acrylic resin is preferable.As specific colorant components which can be contained, black carbonpigments such as RAVEN 420 (manufactured by Columbian Corporation),CARBON BLACK (manufactured by Degussa AG), MONARCH 1000 (manufactured byCabot Corporation), CARBON BLACK 2400 B(Mitsubishi ChemicalCorporation), and the like, blue pigments and green pigments such asHELIOGEN BLUE L-6900, HELIOGEN GREEN L-8605 (manufactured by BASF JapanLtd), PALOMAN BLUE B-4806 (manufactured by Bayer AG), FASTGEN BLUE5030F, FASTGEN GREEN S (manufactured by Dainippon Ink and ChemicalsIncorporated ), and white pigments such as titanium oxide and pigmentswith other colors.

Further, with a view to improving designs, metal fine particles orglittering pigments can be added to coloring components. Moreover,coloring components can be used alone or in combinations of two or moreof them. In addition, in order to provide a decorative film with aplating toned design, decorative layers 35 and 45 can be a metal thinfilm layer prepared by a forming method of a metal thin film layer. As ageneral method of forming a metal thin film layer, spattering method orvapor deposition method and the like can be cited.

When metal thin film are built up in a primer layer, for example, when aspattering method is used, spattered metal is repelled and therefore isnot built up. However, by containing cross-linking agents such asisocyanate in a primer layer, a metal thin film can be formed. In thiscase, kinds of metals are not specifically limited as long as they aremetals capable of forming a metal thin film by these methods. Examplesof usable metals include chrome, aluminum, titanium, gold, silver, andthe like. In addition, alloy can be used using several kinds of metals.

When decorative layers 35 and 45 are provided, in order to strengthenbonding between decorative layers 35 and 45 and resins 12 and 22 curedby radiation, the second primer layer can be provided between decorativelayers 35 and 45 and resins 12 and 22cured by radiation. Although resinsused in the second primer layer 16 are not specifically limited, whensuch resins cured by radiation which are composed of, in particular,acrylic olygomer and/or acrylic resin are used in not less than 25% by.weight, a decorative film excellent in weather resistance,abrasion-resistance, solvent resistance, and chemical resistance withlittle contraction rate can be provided.

A decorative film 20 of the present invention can be prepared by suchways that an adhesive layer 23 is formed in a decorative film 10 of theabove composition and that a releasing sheet 24 is applied forprotecting the adhesive layer. By preparing a decorative film havingsuch a composition, workability at an operational site in which adecorative film is adhered to a substrate become easier and smoothtransition from an operational site for preparing a decorative film toan operational site for adhering a decorative film is realized.

Although an adhesive which can be used for forming an adhesive layer 23is not specifically limited, it is necessary to use an adhesive with aproperty of chemically bonding with a molecular chain of a resin in aprimer layer 21 and it is preferable to use an adhesive excellent inweather resistance. Examples include acrylic adhesive J which containsboth acrylic polymer and an adhesion imparting agent. Here, as amonomeric unit which composes an acrylic polymer of an acrylic adhesive,(meth)acrylate alkyl ester including methyl(meth)acrylate,ethyl(meth)acrylate, propyl(meth)acrylate, butyl(meth)acrylate, and thelike can be exemplified.

Further, as adhesion imparting agents, such agents as rosin adhesionimparting agents, terpene adhesion imparting agents, phenol adhesionimparting agents, coumarone adhesion imparting agents, and the like canbe exemplified.

A thickness of an adhesive layer 23 is preferably 30 to 100 μm and morepreferably, 35 to 80 μm. When a thickness of an adhesive layer 12 isless than 30 μm, it is possible that adhesive strength is not enoughwhen a decorative film 10 is adhered to a substrate. On the other hand,when a thickness of an adhesive layer 12 is greater than 100 μm, itbecomes unnecessarily thick and therefore is not cost-effective.

As for a releasing sheet 24, it is not specifically limited as long asan adhesive does not bond, and examples include film type sheet such aspolyethylene terephthalate, polyethylene, polypropylene, and the like,or paper type sheet such as quality paper or craft paper and the like onwhich a releasing agent such as silicone and the like is coated on. Athickness of a releasing sheet is preferably 25 to 50 μm from a viewpoint of easy handling and cost-effectiveness.

In use, after a bond is applied to a decorative film 10 without anadhesive layer or to a substrate surface to which a decorative film 10,is applied, a decorative film is provided in such a way as to closelycontact with a substrate surface and is bonded to a substrate surfaceand integrated via a bond. After bonding, in order to make across-linking agent react, a cross-linking agent must be heated and/orpressurized to some degree or more.

Further, this decorative film can be used as a paintless film used forblow molding method, insert molding method, film in mold method, SMCmolding method, PFM molding method, and the like.

On the other hand, in the case of a decorative film 20, a releasingsheet 25 is peeled off and is adhered to a substrate.

(Production Method)

Next, a production method of decorative films 10 and 20 of the presentinvention is explained in detail referring to FIG. 5.

As shown in FIG. 5(a), the first step for producing the decorative film10 in the present invention is conducted first by printing a primerlayer 51 provided with a releasing property to a releasing surface on asurface of a releasing sheet for transfer 56. The primer layer 51 iscomposed of a resin having a functional group in a molecular chain towhich a cross-linking agent reacts and a releasing property to areleasing sheet for transfer.

For information, when a cross-linking agent is mixed with a resin usedin the primer layer 51 and/or an adhesive in a forming step of anadhesive layer 53 which is stated later, a conventional method formixture can be adopted.

Here, as shown in FIG. 5(c), following the first step, the second stepis further the step to print an ink which contains a coloring componentand to provide a decorative layer 55. A decorative layer 55 can beprepared not only by a printing method but also by a general metal thinfilm production method using a primer layer containing a cross-linkingagent depending on the case for example when a metallic luster isdesired or the like.

For information, in order to obtain a colorless decorative film, thesecond step is omitted.

As shown in FIGS. 5(b) and (d), the third step is conducted by applyinga curable resins to the substance obtained by the second step. Forexample, when a resin cured by an electron ray is used, the third stepis conducted by applying non-solvent type resin coating 52′ cured byelectron ray which composes a curable resin layer 52 on a layer built upin the second step.

The forth step is conducted by forming a curable resin layer 52 whichcures a non-cured resin by irradiating. For example, in the case ofexemplified third step, a non-solvent-type resin coating 52′ cured byelectron ray is put in an electron ray irradiating device in a non-curedstate and by applying an electron ray irradiation, the non-solvent-typeresin coating 52′ is cured.

When cured the coated curable resin coating 52′ to form a curable resinlayer 52, the primer layer 51 and the decorative layer 55 aretransferred from the releasing sheet for transfer 56 to the curableresin layer 52.

By releasing a releasing sheet for transfer 56 from the substanceobtained by the above steps, a decorative film 10 as shown in FIG. 1 canbe obtained.

Further, in order to obtain a decorative film 20 having an adhesivelayer, the fifth and sixth step as shown below are necessary.

As shown in FIG. 5(e) and (f), the fifth step is the step to form anadhesive layer 53 in a decorative film 10. An adhesive layer 53 isformed by applying an adhesive including a cross-linking agent to areleasing sheet 54, followed by making the adhesive layer 53 adhere toan exposed primer layer 51 by peeling off the adhesive 53 and thereleasing sheet for transfer 56.

The sixth step is the step to heat curing a film obtained in the fifthstep and to transfer the adhesive layer 53 from the releasing sheet 54to the primer layer 51. The state for heat curing is left to stand for 3days at a temperature of 50° C. At this time, a cross-linked material isprovided between the primer layer 51 and the adhesive layer 53.

Through such steps, a decorative film 20 of the present invention can beobtained.

The aforementioned decorative film is excellent in design, abrasionresistance, and solvent resistance, and in particular, excellent indurability. Therefore, it can be used for construction componentsincluding walls, columns, doors, and the like, for vehicles and vessels,and for billboards and signs. In particular, the decorative film of thepresent invention can preferably be used for bumpers, sash tapes forminor parts, films for automobile display, further for a coating ofautomobile bodies.

EXAMPLES

Hereinafter, the examples of the present invention are explained indetail.

Example 1

Aromatic isocyanate as a cross-linking agent (trade name: L-55 E,manufactured by Nippon Polyurethane Industry Co., Ltd) was mixed to anacrylic resin with substantial ratio of 0.85%. Then, a resin componentwhich contains the cross-linking agent was solidly printed with athickness of 4 μm as a primer layer on a whole surface of a releasingsurface of a releasing sheet for transfer with releasing auxiliary layerprovided for a surface of untreated polyester film (manufactured byToyobo Co., Ltd) with a thickness of 32 μm.

This sheet built up by a primer layer was taken and a transparentnon-solvent type electron ray resin coating (main component thereof is acompound of urethane acrylate resin and tripropylene glycoldiacrylatemanufactured by SANYU-PAINT Co., Ltd) was applied on the primer layer bya gravure coating method in a thickness of 75 μm. Then, on this resincoating cured by electron rays, polyester embossed film (manufactured byToyobo Co., Ltd) with a thickness of 32 μm having uneven surfaces likefrosted glass was provided as a releasing sheet and was put in anelectron irradiation device (manufactured by Nisshin Electrics, Ltd,curtain beam method) in a nitrogen atmosphere in a way that the unevensurface is fitted to a resin coating cured by electron rays.

Then, 4 Mrad electron ray with an accelerated voltage of 250 kV. wasirradiated, and the resin coating was cured, thereby forming a curableresin layer and a decorative film was obtained.

Next, in order to form an adhesive layer, an acrylic adhesive (X-0589manufactured by VIG TEQNOS LTD) was applied to a releasing sheet ofquality paper with silicon coating. From a decorative film, thereleasing sheet for transfer was released. And to the exposed primerlayer with a releasing sheet removed, this releasing sheet of qualitypaper was applied. Then, it was left to stand as it is for three days ata temperature of 50° C., transferred, and adhered. Through this step, adecorative film was obtained.

Releasing test was conducted again for an obtained decorative film. Thistest is adopted to examine the amount of a material which comprises thedecorative film including an adhesive or the like remained on an SUSplate when an SUS plate. The procedure was as follows: An SUS plate wasapplied to an exposed adhesive layer with the releasing sheet removed.Next, one shuttling on a decorative film was applied to an SUS plate bya rubber roller with a loading of 2 kg/cm². Further, this was heated for30 minutes with a temperature of 80° C. Then, after left to stand for 24hours at a room temperature, a decorative film was peeled off at a speedof 300 mm/minute in an angle of 180°.

After this test, if there remains an adhesive (paste remaining ratio),it can be the that a releasing between layers is likely to occur.

When the test for a releasing property was conducted again on adecorative board obtained in this Example, a releasing occurred betweenan SUS plate and an adhesive layer and the paste remaining ratio was 1%.

Example 2

A decorative film was produced by the same method as in Example 1 exceptthat aromatic isocyanate as a cross-linking agent (trade name: L-55 E,manufactured by Nippon Polyurethane Industry Co., Ltd) was mixed to anacrylic resin with substantial ratio of 1%. When a releasing test wasconducted by the same method as in Example 1, a releasing occurredbetween a decorative film and an adhesive layer, and the paste remainingratio was 0.1%.

Example 3

A decorative film was produced by the same method as in Example 1 exceptthat aromatic isocyanate as a cross-linking agent (trade name: L-55 E,manufactured by Nippon Polyurethane Industry Co., Ltd) was mixed to anacrylic resin with substantial ratio of 2%. When a releasing test wasconducted by the same method as in Example 1, a releasing occurred andthe paste remaining ratio was 0%

Example 4

A decorative film was produced by the same method as in Example 1 exceptthat aromatic isocyanate as a cross-linking agent (trade name: L-55 E,manufactured by Nippon Polyurethane Industry Co., Ltd) was mixed to anacrylic resin with substantial ratio of 3%. When a releasing test wasconducted by the same method as in Example 1, a releasing occurred andthe paste remaining ratio was 0%. From the result of Examples 1 to 4, itwas found that in a decorative paper sheet of the present invention, asthe ratio of isocyanate increases, a bonding between layers getsstronger. Therefore, it can be that the decorative film of the presentinvention is excellent in durability.

Example 5

Acrylic resin was solidly printed with a thickness of 4 μm as a primerlayer on a whole surface of a releasing surface of a releasing sheet fortransfer which has releasing auxiliary layer provided for a surface ofuntreated polyester film (manufactured by Toyobo Co., Ltd) with athickness of 32 μm. Next, a grained decorative layer was printed by agravure method with a thickness of 4 μm using acrylic resin layer on theprimer layer. This sheet built up by a primer layer and a decorativelayer was taken and a transparent non-solvent type electron ray resincoating (main component thereof is a compound of urethane acrylate resinand tripropylene glycoldiacrylate manufactured by SANYU-PAINT Co., Ltd)was applied on a decorative layer by a gravure coating method in athickness of 75 μm.

This was cured by the curing method shown in Example 1. Next, aromaticisocyanate as a cross-linking agent (trade name: L-55 E, manufactured byNippon Polyurethane Industry Co., Ltd) was mixed to an acrylic adhesive(X-0589 manufactured by VIG TEQNOS LTD) with a substantial rate of 2%.An adhesive layer was prepared in the same step as shown in Example 1.When the test for a releasing property was conducted again on theobtained decorative film, a releasing occurred between an SUS plate andan adhesive layer and the paste remaining ratio was 0%. In addition,flaws such as wrinkling, cracking, and the like could not be seen in agrained design. From this result, it can be that in a decorative papersheet in the present invention, the problem of a releasing is hard tooccur and the decorative film of the present invention is excellent indurability.

Example 6

Aromatic isocyanate as a cross-linking agent (trade name: L-55 E,manufactured by Nippon Polyurethane Industry Co., Ltd) was mixed to anacrylic adhesive (X-0589 manufactured by VIG TEQNOS LTD) with asubstantial rate of 1%. A resin component was solidly printed with athickness of 4 μm as a primer layer on a whole surface of a releasingsurface of a releasing sheet for transfer which has releasing auxiliarylayer provided for a surface of untreated polyester film (manufacturedby Toyobo Co., Ltd) with a thickness of 32 μm. Next, this sheet was putin a spattering device and silver was built up with a thickness of 1 μmon this primer layer by a spattering method, thereby preparing adecorative layer. This sheet with a decorative layer built up was takenand a transparent non-solvent type electron ray resin coating (maincomponent thereof is a compound of urethane acrylate resin andtripropylene glycoldiacrylate manufactured by SANYU-PAINT Co., Ltd) wasapplied on a decorative layer by a gravure coating method in a thicknessof 75 μm. Then, a releasing sheet for transfer of a decorative film waspeeled off and an acrylic resin bond was applied to the exposed primerlayer and was bonded on a surface of SUS plate via a bond and using aroll press in a state of 40° C. and pressurizing 1.6 kg/cm², therebyobtaining a decorative board.

The obtained decorative board had a finish with plating tone. When arepeated releasing test was conducted by the same method as shown inExample 1, a releasing occurred between an SUS plate and an adhesive andthe paste remaining ratio was 3%. However, this is assumed to be aresult that a bonding force was stronger than an adhesive force.Therefore, it can be that the decorative board is excellent indurability in which release between layers and the like are hard tooccur.

Comparative Example 1

A decorative film was obtained by the same step as in Example 1 exceptfor the mixture of an isocyanate, a cross-linking agent. When areleasing test was conducted again, a breakage occurred and the pasteremaining ratio was 8%. From this result, compared with a decorativefilm of the present invention, a decorative film of Comparative Example1 is more likely to cause release between layers.

Comparative Example 2

A decorative film was obtained by the same step as in Example 5 exceptfor the mixture of an isocyanate, a cross-linking agent. When areleasing test was conducted again, a breakage occurred and the pasteremaining ratio was 12%. Some wrinkles were observed in a graineddesign. From this result, compared with a decorative film of the presentinvention, a decorative film of Comparative Example 2 is more likely tocause release between layers.

Comparative Example 3

A decorative film was tried to be obtained by the same step as inExample 6 except for the mixture of an isocyanate, a cross-linkingagent. However, a silver was not built up in a spattering method and adecorative film could not be obtained.

Comparative Example 4

Since it was found that a silver was not built up in Comparative Example3, a resin cured by an electron ray in the Example 6 was coated withoutbuilding up a silver. Then, a decorative board was obtained by the samemethod as in Example 6. When a releasing test was conducted on thisdecorative board, a breakage occurred inside of a primer layer and thepaste remaining ratio was not less than 50%. From this result, it wasinferred that a decorative film of Comparative Examples is more likelyto cause release between layers than a decorative film of the presentinvention.

As above mentioned, since a strong chemical bonding occurs in adecorative film over a surface between a primer layer and a bond or anadhesive, a decorative film can be obtained in which a releasing from asubstrate is hard to occur even when used for a long period of time.

Therefore, a decorative film of the present invention can be used forconstruction components including walls, columns, doors and the like,for vehicles and vessels, for billboards and signs. Among them, adecorative film of the present invention can preferably be used formodified automobile parts or modified automobiles including exteriorsincluding automobile bodies and the like, bumpers, automobile interiordisplays including mirrors and the like, in which a good performanceunder harsh condition is required.

While illustrative embodiments of the present invention have beendescribed herein, the present invention is not limited to the variouspreferred embodiments described herein, but includes any and allembodiments having modifications, omissions, combinations (e.g., ofaspects across various embodiments), adaptations and/or alterations aswould be appreciated by those in the art based on the presentdisclosure. The limitations in the claims are to be interpreted broadlybased the language employed in the claims and not limited to examplesdescribed in the present specification or during the prosecution of theapplication, which examples are to be construed as non-exclusive. Forexample, in the present disclosure, the term “preferably” isnon-exclusive and means “preferably, but not limited to.”Means-plus-function or step-plus-function limitations will only beemployed where for a specific claim limitation all of the followingconditions are present in that limitation: a) “means for” or “step for”is expressly recited; b) a corresponding function is expressly recited;and c) structure, material or acts that support that structure are notrecited.

1. A decorative film, comprising: an adhesive layer including across-linking agent; a primer layer formed on the adhesive layer; adecorative layer including an ink and formed on the a primer layer; anda curable resin layer cured by radiation, formed on the decorativelayer, wherein the primer layer contains a resin having a functionalgroup in a molecular chain to which the cross-linking agent reacts and areleasing property to a releasing sheet for transfer, and wherein across-linked resin material is included between the adhesive layer andthe primer layer.
 2. The decorative film as set forth in claim 1,wherein the cross-linking agent included in the adhesive layer is anisocyanate cross-linking agent and wherein a functional group of amolecular chain of the resin used in the primer layer is at least eithercarboxyl group or hydroxyl group.
 3. The decorative film as set forth inclaim 1, wherein the cross-linking agent included in the adhesive layeris an isocyanate cross-linking agent and wherein the primer layercontains vinyl chloride vinyl acetate copolymer resin or acrylic resinin a total of not less than 25% by weight.
 4. The decorative film as setforth in claim 1, wherein the decorative film has a releasing sheet toprotect the adhesive layer applied on the adhesive layer.
 5. Aproduction method of a decorative film, comprising: the first step inwhich a primer layer is formed by applying a resin having a functionalgroup in a molecular chain to which a cross-linking agent reacts and areleasing property to a releasing sheet for transfer on a surface of thereleasing sheet, the second step in which a decorative layer includingan ink is printed on the primer layer; the third step in which a curableresin layer cured by radiation is applied on the decorative layer: theforth step in which the primer layer and the decorative layer aretransferred from the releasing sheet for transfer to the curable resinlayer when the curable resin layer is cured by radiation; the fifth stepin which an adhesive including the cross-linking agent is applied on areleasing sheet to form an adhesive layer, and then, the adhesive layeris adhered to the exposed primer layer by peeling off the releasingsheet for transfer; and, the sixth step in which a cross-linked resinmaterial is provided between the primer layer and the adhesive layer aswell as heat curing of the film obtained in the fifth step brings theadhesive layer to transfer from the adhesive layer to the releasingsheet.
 6. A decorative film, comprising: an adhesive layer including across-linking agent; a primer layer formed on the adhesive layer; and acurable resin layer cured by radiation, formed on the primer layer and,wherein the primer layer contains a resin having a functional group in amolecular chain to which the cross-linking agent reacts and a releasingproperty to a releasing sheet for transfer, and wherein a cross-linkedresin material is included between the adhesive layer and the primerlayer.
 7. The decorative film as set forth in claim 6, wherein across-linking agent included in the adhesive layer is an isocyanatecross-linking agent and wherein a functional group of a molecular chainof a resin used in the primer layer is at least either carboxyl group orhydroxyl group.
 8. The decorative film as set forth in claim 6, whereinthe cross-linking agent included in the adhesive layer is an isocyanatecross-linking agent and wherein the primer layer contains vinyl chloridevinyl acetate copolymer resin or acrylic resin in a total of not lessthan 25% by weight.
 9. The decorative film as set forth in claim 6,wherein the decorative film has a releasing sheet to protect theadhesive layer applied on the adhesive layer.
 10. A production method ofdecorative film, comprising: the first step in which a primer layer isformed by applying a resin having a functional group in a molecularchain to which a cross-linking agent reacts and a releasing property toa releasing sheet for transfer on a releasing surface of the releasingsheet, the second step in which a curable resin layer cured by radiationis applied on the primer layer: the third step in which the primer layeris transferred from the releasing sheet for transfer to the curableresin layer when the curable resin layer is cured by radiation; theforth step in which an adhesive including the cross-linking agent isapplied on a releasing sheet to form an adhesive layer, and then, theadhesive layer is adhered to the exposed primer layer by peeling off thereleasing sheet for transfer; and, the fifth step in which across-linked resin material is provided between the primer layer and theadhesive layer as well as heat curing of the film obtained in the forthstep brings the adhesive layer to transfer from the adhesive layer tothe releasing sheet.